Two New Haulers Feature AdvancedAC Drive Systems
The latest version of its AC system, the company explained, couples the AC drive with new control software jointly developed with other Hitachi Group companies and uses various sensors that provide information on driving conditions; as a result, tire slippage is reduced on acceleration as well as tire lock-up during braking, while chassis oscillation in a front-rear direction and tire skid while steering are now prevented. For additional improvement, the two models are equipped with electric brakes that are activated during downhill driving. These trucks do not require the use of mechanical brakes during normal driving, resulting in smoother deceleration as well as reduced maintenance.
Hitachi offers a choice of engines from two different suppliers—Cummins or MTU—for the two new models, and this option will also apply to the EH5000AC-3 model launched in 2013.
Additional features available on the
new models include:
• A temperature sensor has been added
to the bearing area of the alternator and
drive motors. An alarm sounds when
the sensor detects abnormal heat emission,
and restricts driving operations
to prevent damage to the machine.
• Improvements to the nominal payload
measurement system that reduce measurement
errors by reflecting changes
in fuel weight in payload calculation.
• An evacuator exhaust valve for the engine
suction filter and an electric grease
pump have been added to further improve
daily maintainability. Other standard
features for maintainability include
a trailing arm front suspension that permits
strut removal without tire removal,
a centralized auto-grease system that
can be accessed from the ground, a bat
tery and relay box located in the front
bumper for easy access, and a maintenance
deck in the rear of the cab.
• A high level of interchangeability for
common engine and hydraulic system
components used in Hitachi's other
dump trucks and ultra-class hydraulic
excavators.
www.hitachi-c-m.com